Comment 12 for bug 773979

I'm not an expert on Gnome Shell's behavior, since I don't use it. I'm just going by what their developers wrote.

Auto-whitelisting the way you describe would be equivalent to having the old-style notification area, plus a notification when an application first launches, plus notification area items disappearing weeks after the application was installed. I'm fairly sure that there would be no understandable way of wording the notification that people would understand. (If explained in enough detail, it would be too long to bother reading. And suggesting that the user report a bug would be the software equivalent of breaking the fourth wall.) And a notification area item disappearing weeks later would seem capricious.

I just checked with the Unity 2D maintainer and he verified that the whitelist works there.